Update actions/setup-go action to v6

Author: renovate[bot]

.github/workflows/ci.yml

@@ -69,7 +69,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Setup Go ${{ matrix.go-version }}
-        uses: actions/setup-go@v5
+        uses: actions/setup-go@v6
         with:
           go-version: "${{ matrix.go-version }}"